6.1.25

As part of a survey of statistics students, they were asked if they had ever been in a car crash while they were driving and how many minutes of exercise they had on the previous day. The data fileCarCrashExercise.txt(link: http://www.isi-stats.com/isi/data/chap6/CarCrashExercise.txt) has these results. Copy and paste this data set into theDescriptive Statistics applet (link:http://www.rossmanchance.com/ISIapplets.html).

Questions:

• Based on just how the distributions look, do you think there is an association between being in a car crash while driving and exercise? If so, in what way?

A) No, since the distribution of exercise seems about equal for the two groups.

B) Yes, maybe, since the distribution of exercise seems less skewed for the no-car-crash group than the car-crash group

C) Yes, maybe, since the distribution of exercise seems more skewed for the no-car-crash group than the car-crash group

• Find the mean of number of minutes of exercise for those that have been in car crashes while driving and those that have not. With this added information, do you think there is an association between being in a car crash while driving and exercise?

A) Mean: 32.375 (no crashes), 32.375 (crashes). There is no association, since the means are the same.

B) Mean: 57.037 (no crashes), 32.375 (crashes). There is an association, since the means are different.

C) Mean: 57.037 (no crashes), 57.037 (crashes). There is no association, since the means are the same.

D) Mean: 32.375 (no crashes), 50.037 (crashes).There is an association, since the means are different.

• Find the median number of minutes of exercise for those that have been in car crashes while driving and those that have not. With this added information, do you think there is an association between being in a car crash while driving and exercise?

A) Median: 30 in each group. There is no association, since the medians are the same.

B) Median: 34 in each group. There is no association, since the medians are the same.

C) Median: 30 (no crashes), 34 (crashes). There is an association, since the medians are different.

D) Median: 34(no crashes), 30 (crashes). There is an association, since the medians are different.